The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Control systems for controlling the power output applied to a heating element or other power-receiving device are well known in the art. In particular, U.S. Pat. No. 3,752,956 to Cahill et al.; U.S. Pat. No. 4,582,982 to Peigari; 4,894,520 to Moran; and U.S. Pat. No. 5,624,591 to Di Trapani all disclose some type of controller for controlling the power output to a heating element. Specifically, the Peigari reference teaches an SCR power controller in which the output voltage to a resistance heater is varied in accordance with outside temperature, while the Moran reference applies a variable current to a resistance heater corresponding to variations in supply voltage by using a pulse width modulator which controls the timing of a switching device in order to control the flow of current through the resistance heater. Additionally, the Cahill et al. reference discloses a fixing circuit in arrangement with a gated triac and feeding circuits for controlling power output to a heating element. Finally, the Di Trapani reference teaches a control circuit comprising a triac for modulating the current supply to a heating element such that the flow of current is interrupted thereto when a predetermined threshold is reached.